Clear lemon-flavored mouthwash

ABSTRACT

Clear lemon-flavored mouthwash compositions are prepared containing water, alcohol, lemon oil, selected nonionic surfactants, and selected anti-bacterial agents.

United States Patent [1 1 Pensak et a1.

[451 Feb. 4, 1975 CLEAR LEMON-FLAVORED MOUTHWASl-l [75] lnventors:Philip Pensak, New Brunswick;

Joseph P. .lanuszewski, Somerville,

both of N11.

[73] Assignee: Colgate-Palmolive Company, New

York, NY,

[22] Filed: Nov. 6, 1972 21 App1.No.:304,040

8/1969 Levinsky et al 424/57 3,514,513 5/1970 Bechtold 424/54 3,639,5692/1972 Medcalf 424/54 3,666,855 5/1972 Muhler 424/54 3,703,583 11/1972Martin 424/54 Primary ExaminerRichard L. l-luff Attorney, Agent, orFirm-Steven J. Baron; Norman Blumenkopf; Herbert S. Sylvester ['57]ABSTRACT Clear lemon-flavored mouthwash compositions are preparedcontaining water, alcohol, lemon oil, se-

lected nonionic surfactants, and selected anti-bacterial agents.

3 Claims, N0 Drawings CLEAR LEMON-FLAVORED MOUTHWASH The inventionpertains to a liquid mouthwash formulation. Specifically, the inventionrelates to a visually clear, stable mouthwash having the stimulating andrefreshing taste of lemon. More specifically, the invention provides astable aqueous mouthwash containing a suitable lemon flavoringingredient. typically lemon oil, lemon juice or a combination thereof.

Liquid mouthwashes are specifically formulated to provide a comfortablefeeling in the'mouth during use. Advantageously, a suitable mouthwashproduct should have a low enough viscosity to permit the user to readilymanipulate and swish it around in his mouth to effectively gargle.Accordingly, the viscosity of a suitable product in accordance with theinvention should be well below 1,000 cps preferably less than about 100cps at room temperature, e.g., from about 1.0 to about 10.0 cps.

To obtain consumer acceptance, a mouthwash formulation must have apleasant flavor. The use of certain specific flavoring ingredients. suchas lemon oil for example, may introduce stability and/or compatibilityproblems in an aqueous mouthwash composition.

The use of lemon oil flavoring in such compositions may result in a hazyproduct or in the settling out of certain components during storage.These undesirable characteristics of a lemon oil flavored aqueousmouthwash may be due to the presence of a high percentage of non-polarterpene components in lemon oil. An additional problem that may arise inan aqueous lemon oil flavored mouthwash is the natural degradation ofthe lemon oil component which can result in an unpleasant tastingproduct.

lt is a primary advantage of the present invention to provide anemulsifying ingredient for lemon oil flavored mouthwash formulationsthat results in a clear, stable product. A further advantage of theinvention is to provide a pH range for aqueous lemon oil containingmouthwash compositions wherein the unpleasant tasting products of thematerial degradation of lemon oil are minimized.

The mouthwash composition according to the invention typically containsfrom about 60 to about 95 percent, preferably 70 to 80, e.g., about 75percent by weight water and from about to about25, preferably to 24,e.g., about l 5 percent by weight ofa non-toxic alcohol such asisopropanol and ethanol. The alcohol component of the mouthwashpreferably utilizes denaturing components which also function asflavoring agents. These materials are exemplified by the followingmaterials: anethol, anise oil, bay oil (eyrcia oil), benzaldehyde,bergamot oil, bitter almond oil, camphor, cedar leaf oil, chlorothymol,cinnamic aldehyde, cinnamon oil, citronella oil, clove oil, coal tar,eucalyptol, eucalyptus oil, eugenol, guaiacol, lavender oil, menthol,mustard oil, peppermint oil, phenol, phenyl salieylate, pine oil, pineneedle oil, rosemary oil, sassa fras oil, Spearmint oil, spike lavenderoil, storax, thyme oil, thymol, tolu balsam, turpentine oil, Wintergreenoil and boric acid. The denaturing agents are typically present in anamount between about 1 and 2 percent of the total alcohol content of themouthwash.

In one specific aspect, the invention provides a nonionic surfactantingredient that effectively emulsifies the lemon oil component in anaqueous mouthwash resulting in a clear, stable formulation. According tothis aspect of the invention, the surfactant ingredient is chosen fromthe group of nonionic surface active agents consisting ofpolyoxyethylene derivatives of sorbitan monodiand tri-fatty acid esterswherein the fatty acid component has between 12 and 24 carbon atoms andthe polyoxyethylene chains contain from about 4 to about 30 ethyleneoxide units and at least 40 percent of the molecular weight ofthemolecule is ethylene oxide. Representative derivatives includepolyoxyethylene sorbitan monolaurate. polyoxyethylene sorbitanmonopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylenesorbitan tristearate, polyoxyethylene sorbitan monooleate. andpolyoxyethylene sorbitan trioleate. Particularly preferred ispolyoxyethylene sorbitan'monoisostearate containing 20 oxyethylene unitsper molecule. The preferred polyoxyethylene (20) sorbitanmonoisostearate emulsifier is a liquid material at room temperature anddoes not adversely affect the flavoring characteristics to theformulation when used in accordance with the invention.

The surfactant component of the new formulation should be present in anadequate amount to completely emulsify the lemon oil flavoring componentto produce a clear, stable product. The concentration of emulsifier istypically from about'0.l to 5 percent of the formulation depending onthe alcohol content and lemon oil concentration. The amount ofsurfactant should be greater for higher amounts of the lemon oilflavoring component and less for smaller amounts of lemon oil. Pursuantto the invention, to obtain a clear, stable lemon oil containing aqueousmouthwash the weight ratio of surfactant to lemon oil in the newformulation should be at least 1.5 to 1, preferably about 10 to l, for aformulation containing about 15 percent alcohol; less for higher alcoholformulations. For non-alcohol containing formulations the weight ratioof emulsifier to lemon oil flavoring should be at least 5 to l to obtaina clear, stable product.

The lemon oil flavoring component is preferably derived from the rind oflemons by methods well known in the art. The lemon oil component of theformulation is present in an amount from about 0.01 to about 1 percent,typically from 0.05 to 1.0 percent, most preferably about 0.1 to 0.5percent, e.g., 0.2 percent by weight depending on the flavoring effectdesired. Of course, an equivalent synthetic lemon oil component may beused if desired.

In addition to, or instead of, the lemon oil component, lemon juicewhich is derived from the pulp of lemons, can be included in themouthwash formulation to further accent the flavor of-the product. Inits natural state, lemon juice can also include lemon oil in amountsranging from 0.25 percent to about 1 percent, typically about 0.5percent. When included in combination with lemon oil, lemon juice can bepresent in any suitable amount, typically from about 5 to 15 percent ofthe formulation. When used instead of lemon oil to flavor an aqueousmouthwash, lemon juice should be present in an amount resulting in anequivalent lemon oil concentration, as previously defined.

The mouthwash composition preferably contains glycerine in amounts up toabout 15 percent, with compositions containing between about 8 and 12percent having particularly desirable characteristics. The glycerinefunctions as a sweetener, supplies body" to the compositions and avelvety feel in the mouth. It may be replaced in whole or in part bysuch equivalent materials as sorbitol or propylene glycol.

3 The mouthwash composition may also optionally contain small effectiveamounts of antibacterial agents such as the quaternary ammoniumcompounds and the substantially saturated aliphatic acyl amides.Preferred additions of these agents are in amounts between about 0.01and 0.1 percent. The following are illustrative of useful antibacterialagents: benzethonium chloride. diisobutyl phenoxy ethoxy ethyl dimethylbenzyl ammonium chloride, N-alkylpyridinium chloride, N-cetyl pyridiniumbromide, sodium N-lauroyl sarcosine. sodium N-palmitoyl sarcosine,lauroyl sarcosine. N- hyristoyl glycine, and potassium N-lauroylsarcosine.

The mouthwash composition will usually also contain adjuvant materialsto provide color, additional flavoring if desired, and sweeteningeffects. Color is typically added in an amount up to about 0.01 percent.Additional flavorant, such as citric acid, or sweetener, such assaccharin, is preferably added in small amounts from about 0.01 to about0.1 percent, typically about 0.05. 1

percent.

Pursuant to a further specific aspect of the invention, the pH of themouthwash formulation is adjusted to from about 3.5 to about 7.0,preferably from about 5 to 6, by the inclusion of a buffering material.By providing the mouthwash with a pH from about 3.5 to about 70,preferably from about 5 to about 6, it has been found that the productsformed by natural degradation of the lemon oil component due tooxidation catalyzed by sunlight are surprisingly not as unpleasanttasting as those found in an equivalent formulation having a-pH belowabout 3.5. The buffering ingredient can be any suitable alkalinematerial that'does not adversely affect the flavor of the formulation.

According to this aspect of the invention, a sufficient amount of thebuffering ingredient to raise the pH of the formulation to the desiredlevel, preferably between about 5 and 6, is included in the lemon oilcontaining mouthwash. Typically, the buffering ingredient is present inan amount from about 0.1 to about 1.0 percent by weight, preferablyabout 0.5 percent. Suitable buffering materials are alkali metal saltsof weak organic acids such as sodium benzoate, sodium citrate,

potassium tartrate and sodium phosphate.

The mouthwash composition can be prepared by methods well known in theart, typically by combining the specified components in an amount ofwater sufficient to bring the total of the components to 100 percent. Itis preferable to admix the alcohol-soluble components in the alcohol ina suitable mixing vessel and then add water to the vessel. Components ofthe mouthwash composition which have greatersolubility in water thanalcohol are preferably added to the water before it is admixed with thealcohol mixture or added to the composition after the water addition.

The following specific examples are further illustrative of the natureof the present invention, but the invention is not limited thereto. Allamounts and percentages through the specification and in the claims areby weight unless otherwise indicated.

EXAMPLE 1 The following mouthwash is formulated:

Percent by Weight Denatured ethanol (95%) 15.00 Polyoxyethylene sorbitanmonoisostearate 1.00

-Continued Benzethoniu m chloride Lemon oil 0.20 Glycerine 10.00 Sodiumsaccharin 0.04 Color (FD&C yellow No. 5; 0.01% 0.60

solution) Dcionized water 73.13 100.00

The denaturing components of the ethanol contain flavoring materials.This formulation is visually clear with a yellow tint, does not separateduring prolonged storage and has a refreshing lemon taste.

EXAMPLE 2 The formulation of Example 1 is reformulated to include 25percent by weight of percent ethanol with a corresponding decrease inthe amount of water presem. I

EXAMPLE 3 The following mouthwash is formulatedzd The denaturingcomponents of the ethanol contain flavoring materials. This formulationis visually clear with a yellow tint, does not separate during prolongedstorage and has a refreshing lemon taste and a pH of about 5.5

EXAMPLE 4 The formulation of Example 3 is reformulated to include 25percent of 95 percent ethanol with a corresponding decrease in theamount of water present.

Percent by Weight EXAMPLES 540 The following mouthwashes having lemonflavors of varying intensities are formulated:

6 chloride. N-alkylpyridinium chloride. N-cetyl pyridinium bromide.sodium N-lauroyl sarcosine, sodium N-palmitoyl sarcosinc, lauroylsarcosinc, N-

Example Number; Percent by Weight lngredient 5 6 7 8 9 l0 Denaturedalcohol (95% 10.0 20.0 25.00 18.00 Emulsifier 0.5 2.00 0.5 5.0 2.00 1.00Lemon oil 0.1 0.20 0.2 1.0 0.10 0.20 Antimicrobial agent" 5.0 0.5 0.80.50 0.05 Glycerine 10.0 15.0 15.00 Buffering agent" 0 50 1.0 0.50 Lemonjuice l0.00 10.00 5.00 Sweetener" 0.] 0.06 0.10 Additional flavorant0.05 0.1 0.05 Deionized water 94.3 87.85 78.3 62.0 62.34 60.10

' Ethanol or isopropunol Preferably polyoxyethylene (20) sorbitanmonoisostearate; polyoxyethylene sorbitan monolaurate, polyoxyethylenesorbitan monopalrnitate. polyoxyethylene sorbitan monostearate,polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitanmonooleate and polyoxyethylene sorbitan trioleate can also be used 1Preferably benzethonium chloride; diisobutyl phenoxyethyoxy ethyldimethyl benzyl ammonium chloride, N- alkylpyridinium chloride, N-cetylpyridinium bromide. sodium N-lauroyl sarcosine, sodium N-palmitoylsarcosine,

N myristoyl glycine and potassium N-lauroyl sarcosine can also be usedSorbitol or propylene glycol can be substituted for glycerine Sodiumbenzoate. sodium citrate, potassium tartrate or sodium phosphate Sodiumsuccharin Citric acid The formulations of Examples, 5, 7 and 8 arevisually clear and stable. Due to the presence of lemon juice, theformulations of Examples 6, 9 and 10 are hazy and contain settleablesolids. They can be filtered to obtain a clear stable product.

Although the present invention has been described with reference toparticular embodiments and examples, it will be apparent to thoseskilled in the art that variations and modifications of this inventioncan be made and that equivalents can be substituted therefor withoutdeparting from the principles and true spirit of the invention.

What is claimed is:

l. A visually clear lemon flavored mouthwash formulation comprising a.from about 60 to about 95 percent by weight of water b. from about 5 toabout 25 percent by weight of an alcohol chosen from the groupconsisting of ethanol and isopropanol c. from about 0.05 to about 1.0percent by weight of lemon oil d. from about 0.1 to about 5.0 percent byweight of polyoxyethylene sorbitan monoisostearate and e. from about0.01 to about 0.1 percent by weight of an anti-bacterial agent chosenfrom the group consisting of benzethonium chloride, diisobutyl phenoxyethoxy ethyl dimethyl benzyl ammonium alcohol chosen from the groupconsisting of ethanol and isopropanol c. from about 0.05 to about 1.0percent by weight of lemon oil d. from about 0.1 to about 5.0 percent byweight of polyoxyethylene (20) sorbitan monoisostearate e. the weightratio of said polyoxyethylene (20) sorbitan monoisostear'ate to saidlemon oil being greater than about 1.5 to l, and

f. a sufficient amount of a buffering agent chosen from the groupconsisting of sodium benzoate, 'sodium citrate, potassium tartrate andsodium'phosphate, to result in a pH of from about 5 to about 6 for saidformulation.

1. A VISUALLY CLEAR LEMON FLAVORED MOUTWASH FORMULATION COMPRISING A.FROM ABOUT 60 TO ABOUT 95 PERCENT BY WEIGHT OF WATER B. FROM ABOUT 5 TOABOUT 25 PERCENT BY WEIGHT OF AN ALCOHOL CHOSEN FROM THE GROUPCONSISTING OF ETHANOL AND ISOPROPANOL C. FROM ABOUT 0.05 TO ABOUT 1.0PERCENT BY WEIGHT OF LEMON OIL D. FROM ABOUT 0.1 TO ABOUT 5.0 PERCENT BYWEIGHT OF POLYOXYETHYLENE (20) SORBITAN MONOISOSTEARATE AND C. FROMABOUT 0.01 TO ABOUT 0.1 PERCENT BY WEIGHT OF AN ANTI-BACTERIAL AGENTCHOSEN FROM THE GROUP CONSISTING OF BENZETHONIUM CHLORIDE, DIISOBUTYLPHENOXY ETHOXY EHTYL DIMETHYL BENZYL AMMONIUM CHLORIDE, N-ALKYLPRIDINIUMCHLORIDE, N-CETYL PYRIDINIUM BROMIDE, SODIUM N-LAUROYL SACROSINE, SODIUMN-PALMITOYL SARCOSINE, LAUROYL SARCOSINE, N-HYRISTOYL GLYCINE, ANDPOTASSIUM N-LAUROYL SARCOSINE F. THE WEIGHT RATIO OF SAID SURFACTANT TOSAID LEMON OIL BEING GREATER THAN ABOUT 1.5 TO
 1. 2. Mouth washaccording to claim 1, including from about 0.1 to about 0.5 percent byweight of lemon oil, wherein said ratio of said surfactant to said lemonoil is about 10 to
 1. 3. A visually clear lemon flavored mouthwashformulation comprising a. from about 60 to about 95 percent by weight ofwater b. from about 5 to about 25 percent by weight of an alcohol chosenfrom the group consisting of ethanol and isopropanol c. from about 0.05to about 1.0 percent by weight of lemon oil d. from about 0.1 to about5.0 percent by weight of polyoxyethylene (20) sorbitan monoisostearatee. the weight ratio of said polyoxyethylene (20) sorbitanmonoisostearate to said lemon oil being greater than about 1.5 to 1, andf. a sufficient amount of a buffering agent chosen from the groupconsisting of sodium benzoate, sodium citrate, potassium tartrate andsodium phosphate, to result in a pH of from about 5 to about 6 for saidformulation.